Functional Magnetic Resonance Imaging Study of Jaw-tapping Movement on Memory Function

• Brain activity of n-back task [ Time Frame: up to 4 weeks ]

  All subjects perform the jaw-tapping and the n-back memory tasks during blood oxygen level dependent (BOLD) fMRI, before and after practicing the jaw-tapping exercise for 4 weeks at home.

  Pre- and post-test fMRI data during the n-back task are analyzed using statistical parametric maps of brain activation.

  
  

• Brain activity of jaw-tapping task [ Time Frame: baseline and 4 weeks ]

  All subjects perform the jaw-tapping and the n-back memory tasks during blood oxygen level dependent (BOLD) fMRI, before and after practicing the jaw-tapping exercise for 4 weeks at home.

  Pre- and post-test fMRI data during the jaw-tapping task are analyzed using statistical parametric maps of brain activation.

  
  

• Performance scores of the n-back task [ Time Frame: baseline and 4 weeks ]
  One-back task performance of each subject is assessed by analyzing responses obtained during scanning.
  
  

Right-handed female volunteers over the age of 50 years with subjective memory complaints are included in the study. Volunteers with dentures, psychoactive medication, history of stroke, or other neurologic disorders are excluded.

The protocol was approved by the Institutional Review Board of university-based hospital.

After administering the Seoul Neuropsychological Screening Battery (SNSB), Mini-Mental State Examination (MMSE) scores above 24 and Clinical Dementia Rating Scale (CDR) scores of 0 are considered subjective memory complaints (SMC), and MMSE scores above 23 and CDR scores of 0.5 are considered MCI.

All subjects undergo two MRI scans. After the first MRI, the subjects are trained to tap their jaws vertically at 1.6 Hz at home twice a day for 30 seconds every day during four weeks.